Delta wave activity occurs most frequently during stage N3 slow-wave sleep,
accounting for 20% or more of the EEG record during this stage.[2] These
waves are believed to originate in the thalamus in coordination with the reticular
formation.[3]

Contents

Throughout the lifespan

Analysis of the waking EEG of a newborn infant indicates
that delta wave activity is predominant in that age, and still
appears in a waking EEG of five-year-olds.[4]
Delta wave activity during slow-wave sleep declines during
adolescence, with a drop of around 25% reported between the ages of
11 and 14 years.[5]

Disorders

High delta wave activity during the waking state is not common
in healthy adults. However, multiple studies have indicated the
presence of increased delta activity in adults during states of intoxication or delirium and in those
diagnosed with dementia or
schizophrenia.[6]